The present invention relates to the art of liquid spray applicators and more particularly to liquid seed applicators. It finds particular application in conjunction with soluble products or non-soluble products, such as grass seed or the like, and will be described with particular reference thereto. However, it will be appreciated that the invention has broader applications such as pelletized fertilizer applications or other uses where it is desired to spread fine solid particles evenly over a surface, and as such may be advantageously employed in other similar environments and applications.
Simple liquid spray applicators are well known in the art and generally utilize a venturi effect, which phenomena is generally described as a reduction in pressure with increasing fluid velocity. Static pressure is exerted on all fluids at rest, the pressure being uniform at all points in a given plane. By the principle of conservation of energy, moving fluids possess kinetic energy by virtue of the movement. Liquid spray applicators take advantage of the principles of the venturi effect to spray a concentrate contained in a reservoir at barometric pressure (static pressure) as a diluted atomized mixture by passing a high velocity input fluid over a capillary tube end to draw the concentrate from the reservoir and out the tube end into the input flow. To maintain static barometric pressure within the container, the reservoir is typically provided with a bleeder passage for input of air at atmospheric pressure.
As one would expect, the liquid spray applicators eventually evolved to include the ability to apply water-soluble products such as, for example, fertilizers or the like. Devices which suggest the capability of spraying soluble products include Gatchet U.S. Pat. Nos. 1,769,428, 1,848,708, and 2,601,672, Flanders U.S. Pat. No. 2,536,361, Roberts U.S. Pat. No. 2,682,428, Elvers, Sr. U.S. Pat. No. 3,123,362, Garrett U.S. Pat. No. 3,165,114, and Dulger U.S. Pat. No. 3,421,738.
According to the spray nozzles available for the application of water-soluble products listed above, an input fluid flow is divided into two partial flows, a first of which is made to mix with a water-soluble solid contained in a reservoir. The mixture in a liquid form escapes the reservoir and combines with a second partial flow in a mixing chamber. As such, a limitation on the rate of application of the contained water-soluble solids is for the most part determined by the rate at which the soluble products can be made to dissolve. In this regard, the use of insoluble products tend to quickly clog the particularly metered orifices of the above-named devices, requiring constant attention to maintaining those passages free from obstruction.
Recently, attempts have been made to develop products for the application of solids in the form of seed or the like. Devices currently offered as being fit for those purposes include Gunlock U.S. Pat. Nos. 4,809,913 and 4,913,356.
Referring to the general principals of operation behind liquid seed applicators available today, an inlet chamber is typically provided for receiving an input fluid flow from a source such as a garden hose. The inlet chambers are typically provided with two exhaust passages including an approach passage having a reduced cross-sectional area and a smaller passage forming an inlet into a reservoir containing seed. The approach passage in turn connects the inlet chamber with a mixing chamber. Within the mixing chamber, the slurry created by the inputted fluid received through the smaller passage and combined with the seed is mixed with the inputted fluid which flows through the approach passage. Lastly downstream, a nozzle is provided for limited control over the resultant spray pattern.
Although the above liquid seed applicators have met with limited success, practical testing of the designs available today, including the designs according to the teachings above, indicates that those devices are extremely limited and promise to clog frequently preventing some portion of the seed from entering the water flow for distribution. With particular reference to the Gunlock patents listed above, it is apparent that the output nozzle is limited to providing only a generally round and concentrated spray pattern which is in most cases inappropriate for providing a desirable even distribution of seed. More particularly, the constrictive output nozzle in effect narrows the mixing chamber, which in turn encourages frequent clogging of the slurry rendering the unit inoperable and/or overflow the container due to over-pressurizing of the unit.
The present invention contemplates a new and improved convertible spray nozzle for use with both water soluble and insoluble products which overcomes the clogging problems heretofore commonly associated with liquid seed applicators, yet while providing for a wide and even pattern distribution of seed or dissolved products.